A brief timeline of the history of Finland.
Stone Age: The longest time period in human history in the area of modern day Finland. There is no evidence of humans in this area in the palaeolithic times (3,3 million years BCE to 10,000 BCE). Humans arrived after the last Ice Age during the mesolithic time (around 9,000 BCE) from east, south, and north (along the coast of Norway). In 8,000 BCE, human settlements were already stable in the area and the culture of the time has been dubbed Suomusjärvi culture by modern humans. These first settlers brought dogs with them, so dogs have existed in Finland as long as humanity.
Neolithic Stone Age (~ 5,000 BCE): People in Finland learned to make clay pottery. Unlike in most places, large scale agriculture was not started in Finland at this time. The first culture of this time period is called Comb Ceramic. Around 2,800 BCE, a new culture called Corded Ware reached the coasts of Finland. People of this culture farmed or at least kept cattle. These newcomers merged with the people already living in Finland, eventually forming the Kiukainen culture, and we have certain proof of farming from this period.
Bronze Age (~ 1,700 BCE): Agriculture spread further in Southwestern Finland, but most of the area of Finland still had hunting and gathering as the most important means of living. Strong connections to Scandinavia were held in the coast areas, bringing in longhouses and burial rock piles. The bronze age and early iron age of inland Finland, on the other hand, is often called Early Metal Age. These people had connections to Central Russia. In this time period, it's believed that there were local chiefs in Finland, and the earliest evidence of the horse is found.
Pre-Roman Iron Age (~ 500 BCE): Earliest signs of iron forging in Finland are in Northern and Eastern Finland, proving that the skill was learned from the east. The Uralic languages much have reached the area as most of the population began to speak the Proto-Sámic language. Life remained mostly similar as during the Bronze Age.
Roman Iron Age (~ 0 CE): Trade routes reached the Roman Empire. Furs were sold in exchange for weapons, jewellery and gold. In Southwestern Finland, there were Germanic settlers likely from Sweden. They spoke a Germanic language that left many important loan words into Finnish, such as äiti "mother", kuningas "king", and rauta "iron".
Migration Period (400-600 CE): Power got centralized to a local peasant elite. In Southern Finland, settled agriculture took over as the most common form of farming in opposition to slash-and-burn cultivation. Ostrobothnia got extremely wealthy thanks to new trade connections.
Merovingian (Vendel) Age (600-800 CE): New, original kind of item types were invented in Finland that weren't just imitations of foreign equivalents. At this point the latest, there were cats in Finland.
Viking Age (800-1050): Scandinavian (Viking) trade brought in many kinds of imported items to Finland, including silver from the Byzantium and the Muslim world.
Early Christian and Crusade Age (1050-1200/1300 CE): Initially, peaceful Christian cultural influence came to Southwestern Finland, as people started to bury bodies into the ground in caskets in Christian fashion (instead of cremation). Hillforts were built in Southern Finland. The time period is believed to have been restless due to many findings of hidden silver stashes. First churches were built. As the name "Crusade Age" implies, two crusades were organized by Sweden to Christianize the Tavastians (1249–1250) and Karelians (1293)... and to take control over the area. The so called "first crusade" against Southwestern Finns is nowadays considered to be fictional. But let's not put all the blame on Sweden: Danes were also involved, and maybe Norwegians too. Germans might have spread the religion in Finland via violent means, as suggested by historian Jouko Vahtola based on German names of church officials in Tavastia in the 13th century. There is no certainty, as "written sources" were written later with the aim to justify invasions and later ruling families.
Middle Ages (1200 CE in the West, 1300 CE in the East): Historical age in Finland began, as from this point on, we have written sources from the time period. In south, west, and parts of east, the Catholic church was in power and the first cities were founded. I must remind that at this point, north and some eastern parts (so most of the inland) were still inhabited by Sámi-speaking pagan hunter-gatherers. All history writing in Finland is biased in favour of the south and west!!!!!! You could argue that in North Savo and Kainuu, the Middle Ages began as late as the 16th century.
Vasa Age (starting 1527): Gustav Vasa declared the Kingdom of Sweden, which half of Finland was a part of, to be protestant (Lutheran) and confiscated the wealth of the Catholic church in his country. For the Western Half, this is the end of the Middle Ages, but as demonstrated, this does not ring true for the other half of the country. For example, areas like North Savo and Kainuu were never Catholic: the first kind of Christianity ever introduced to the area was protestantism in the 17th century (see Imperial Age).
1551: Protestant reformist and student of Martin Luther, Mikael Agricola, invented the Finnish writing system. From his pen also came the first written description of Finnish paganism, which was well alive in Tavastia, Savo, and Finnish Karelia according to his description.
Imperial Age: Began in the early 17th century, when King Gustav II Adolf conquered vast areas around the Baltic Sea, including the "other half" of Finland. The Sámi-speaking hunter-gatherer pagans of the area mixed with Savonians (who were born from Sámi and Tavastian mixing in the 1200s) and Kainuu and inland North Ostrobothnia and Rear Bothnia became Finnish in language and farming in means of living. Church official Johan Cajanus wrote precious information on Finnish paganism in a letter, but also destroyed pagan holy sites in North Savo, tried to permit the people from celebrating Vakat, and pushed for Christian discipline in North Savo and Kainuu. The locals argued that it was their ancestral right to hold whatever celebrations they pleased, though. Runosongs were written down for the first time by various individuals, though in the largest extent by Christfried Ganander. Oh and also first university in Finland, horrible famine in late 17th century AND ALSO Russian genocide on Finns because Russia and Sweden were constantly having wars against each other.
1809: Swedish uppity nobles fucked up and Finland was conquered by Russia, becoming an autonomous Grand Duchy in the Russian Empire.
19th century: Not only did somebody in Europe invent the concept of a "nation", people in Finland started thinking: 'okay we are not Swedes anymore, are we Russians then? But we don't even speak Russian! And to be fair, most of the country apart from the ruling class and west coast peasants don't speak Swedish either...' And then some people read Ganander's stuff and figured we should probably collect and write down more of this ancient oral tradition that was still very much alive in the countryside.
1917: Russia got mogged bad in WWI, resulting in a Civil War in Russia and Finland's declaration of independence.
Civil War, the Finnish front (1918): Communists versus the owning class, fight! (The owning class won).
20th century: Some people were buttmad that other Europeans didn't consider Finns white, so let's have a century of research and identity being painted by the desperate attempt to seem "white enough" for the Germanics. On the other hand, Matthias Alexander Castrén invented "Turanism" to unify Uralic, Turkic, Mongolic, Japanese etc people, all for the term to be now appropriated by Turks for Turkic unity only, lol.
Later than that: Tragic: DNA research shows that Finns do not have a "glorious" history of having arrived from elsewhere as conquerors but are indeed genetically related to the indigenous "lower races", the genetics of West and East Finns are so different they could be considered two separate ethnic groups, and trying to cope with your inferiority complex by oppressing the Sámi in turn in the 1970s was a shitty idea, actually.
Now: Jumala I fucking hope that in the future we can have and form identities based on scientific facts instead of bootlicking for Germanic approval!